Crane with hydraulic jack and adjustable boom



1966 J- TRANCHERO 3, 78,044

CRANE WITH HYDRAULIC JACK AND ADJUSTABLE BOOM Filed Oct. 9, 1964 2 Sheets-Sheet 1 fig. 7

fig. 2

Oct. 11, 1966 J. TRANCHERO 3,278,044

CRANE WITH HYDRAULIC JACK AND ADJUSTABLE BOOM 2 Sheets-Sheet 2 Filed Oct. 9, 1964 United States Patent 3,278,044 CRANE WITH HYDRAULIC JACK AND ADJUSTABLE BOOM Jacques Tranchero, Via Villanovetta 2, Piasco, Italy Filed Oct. 9, H64, Ser. No. 402,770 2 Claims. (Cl. 212-8) The present invention relates to a crane having hydraulic means provided therefor and a boom or loading arm which is adjustable in length. More particularly, this invention relates to a crane characterized by the fact that the boom, adjustable in length and actuated underneath by a hydraulic piston, is pivotable with respect to the fixed column of the crane through a play of levers which form a couple or dual system of polygons (pantograph) with movable sides. This particular articulation of the boom allows it a considerable movement in the vertical plane.

The cranes of the prior art have been lacking sufiicient vertical movement because of the structural deficiencies thereof. It was heretofore impossible, for example, to lower the loading arm below the ground level of the crane base. This is now possible thanks to the present inventive device, the main structural characteristics of which are concisely given hereinbelow.

From a support base, which may be either fixed or pivotable, a hydraulic piston and cylinder (also called lifting jack) project themselves upwardly to actuate and rise the boom either directly or through a couple of connecting rods or plates which are symmetrical to one another.

The hydraulic piston is connected pivotably to the base of the crane, in which case it cooperates with a vertical riser fixedly connected to said base. The riser has connected to its upper extremity a number of levers which form, when in operation, a couple of irregular and moving polygons which constitute an intermediate connection between the upper extremity of the supporting riser and one extremity of the boom, said extremity of the boom being opposite to the load-carrying extremity thereof.

In accordance with a first variance of the embodiment of the present invention, from the support base of the crane there is projecting upwardly a hydraulic piston, the cylinder of which has its lower extremity fixedly connected to the base of the crane, thus replacing the riser itself. At the upper extremity of the fixed cylinder, there are provided two parallel risers, oriented along the line of force of the cylinder and effecting the same play of levers which create the couple of moving polygons which connect the boom of the crane with the fixed vertical riser discussed hereinbefore.

Finally, the practical employment of the crane of the invention necessitates the use of a pair of trusses parallel to each other, upperly pivotably connected to the sides of the boom and rigidly connected at their lower ends .to angle-type brackets which are adjustable in length and form a loading platform. This platform, in its resting position, may be lowered to the level of the crane base and is capable of lifting to an intermediate height considerable loads such as, particularly, automotive vehicles.

From the above concise representation, it can be seen that the crane of the invention, besides being a device capable of a multitude of operations in the most unrelated fields, solves heretofore unsolvable problems in lifting apparatus.

The inventive characteristics of the crane of the invention will become more apparent from the following detailed description and from the accompanying drawings, which are here given solely as illustrative examples of the invention without unnecessary limitations on the scope of the invention, and in which drawings:

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FIGURES 1, la, 1b, 2 and 2d represent schematically the principle of operation of the crane;

FIGURE 3 shows perspectively and assembled the crane of the invention according to one specific embodiment, namely, the lifting of loads such as automotive vehicles and adapted to be used as a mobile bridge for car greasing and related inspection;

FIGURE 4 is a partial side view of the crane of FIG- URE 3;

FIGURE 5 is a frontal detailed view of the brackets of the cranes; and

FIGURE 6 is a top view of the brackets of FIGURE 5 taken along the plane indicated by the sectional arrows of FIGURE 5.

Referring now to FIGURE 1 of the drawings, the essential components of the crane are:

The base 10, rigidly fixed or pivotable or provided with moving means such as casters, any one of these variances, depending on the ultimate employment of the crane;

The vertical riser 12 which has its lower end fixed connected to the support base 10 and its upper end pivotable about the extremities of the levers 14 and 16. The opposite extremities of levers 14 and 16 are pivotable about the end 18a of the boom 18 by mean-s of shackles or short levers 20. To the base 10 is connected at 22a the hydraulic cylinder 22 with piston 24 the extremity 24a of which is pivotable at 18b of the boom 18. The cylinder 22 can oscillate in a vertical plane which coincides with the vertical plane on which the boom 18 oscillates. At the extremity of the boom 18 there is applied the load to be lifted. In this condition, the oscillation points 12a, 12b, 14a and 18a represent the apexes of two irregular polygons formed by the levers. This may be visualized as resembling the operation of a pantograph. These levers are symmetrical and parallel .to one another, As it can be seen from the drawing, only those levers relative to one side of the crane are visible (14, 20, 16 and, partially, 12c of riser 12).

In FIGURE 1, in dotted lines, there is represented the crane with the boom 18 fully lowered, while in solid lines, there is represented the boom 18 in position of maximum elevation. As it can be clearly seen from the schematic drawings, the extremity of boom 18 is capable of traversing vertically along the broken line shown between the arrows for a distance ranging practically from the floor to the maximum elevation allowed by the boom length itself and this because of the pivoting action of connecting joint 22a of cylinder 22 with respect to the base 10 and because of the polygons formed by the intermediate levers 12c, 14, 20 and 16, pivoting between column 12 and point 18a of the boom.

Substantially, by the action F of the lifting jack 22-24, a differential movement is imposed upon the play of the levers of the crane, which movement actuates the boom 18 as a third-class lever and permits the extremity 18c thereof to move along the vertical trajectory indicated by the direction of the downwardly pointing arrows (FIG- URE 1).

FIGURES la and 1b show in detail another variance of the invention with respect .to the pivoting point of the column or riser 24 in relation to the boom 18. This variance calls for the use of a couple of connecting rods or plates (only one is visible from the figures) which are symmetrical and which have their upper extremities pivotable at 28 with the extremity of the stem 24 and their lower extremities pivotable at 30 with the boom 18. This arrangement allows a greater inclination of the boom 18, the loading end of which can reach a level considerably lower than that of the base of the crane.

In the embodiment shown in FIGURE 2, the riser 12 is eliminated and is replaced by the cylinder 22 which is fixed to the base 10. The structural configuration of the polygons formed by the couples of levers 14, 16, 12c and 20 does not vary, but the extremity 24a of the piston 24 is connected to a roller 30a provided on the boom 18 in a suitable position along the same. This arrangement allows a movement of the lifting jack perfectly vertical and is, thus, suitable for certain specific uses of the crane, particularly when the space for the erection of the crane is somewhat limited, such as, for example, in the case of wheeled cranes or mounted on motor vehicles. Finally, for cranes which rotate on a 360 arc, the entire assembly is considerably simplified, because the entire assembly may be rotated easily about the axis of the cylinder 22 which replaces column 12.

Also in this embodiment, there are provisions for employing connecting rods or plates 26 (FIGURE 2a), pivotable and positioned intermediate piston 24 and boom 18, as it was the case of the arrangement of FIG- URES 1a and 1b.

A representation of the practical materialization of the crane of the invention is given perspectively in FIGURE 3 and in some details of FIGURES 4, 5 and 6. This arrangement of a lifting jack 22-24 oscillating on a vertical plane is substantially characterized by the fact that to the boom 18, preferably adjustable in length, telescopically by hydraulic means, there is pivotably connected at 18d a strong pendular truss 34 which has its lower end terminating with T-square projections 34a, 34b adjustable in length. The truss 34 is provided with rollers (of the gear bed type) 36 which, due to gravity of the truss itself, connect frontally the corresponding roller guides 12d located Within the trusses or risers 12. The regulation and adjustment in length of the T-square projections 34a, 34b of truss 34 is obtained by means of telescopic brackets 38, 40 which may be blocked in position by means of bolts or other suitable means. In this event, as shown in FIGURES 1, 4 and 6, the crane is provided with a sufliciently wide support base, such as, for example, by means of diverging beams 42, cooperating with feet 44 and supplied with casters or the like for movement of the entire assembly.

As shown in detail and in dotted lines in FIGURE 4, the plane of support A obtained by the brackets of truss 34 reaches, when fully lowered, substantially the level of the ground plus the thickness of the T-square projections 34a with related mobile brackets 40.

The crane hereinabove described may be employed for lifting any considerably heavy weight resting on the floor and, particularly, for lifting automotive vehicles as explained above. The utilization of the device of the inventoin has practically unlimited range and the scope of the claims should not be limited to the illustratively given interpretations thereof.

What is claimed is:

1. A crane comprising a support base; a riser connected at its lower extremity to said support base; a pair of levers pivotably connected at a first end thereof to the upper extremity of said riser; a boom pivotably connected at one terminus thereof to the second end of said levers; and a lifting jack comprising a cylinder and a piston within said cylinder, said piston being connected to said boom at a point intermediate the termini of said boom; characterized in that said cylinder of said lifting jack and said riser are individually and independently connected to said support base, the former pivotably and the latter fixedly.

2. A crane comprising a movable support base; a riser connected at its lower extremity to said support base; a pair of levers pivotably connected at a first end thereof to the upper extremity of said riser; a boom pivotably connected at one terminus thereof to the second end of said levers; a lifting jack pivotably connected to said base and comprising a cylinder and a piston within said cylinder, said piston being connected to said boom at a point intermediate the termini of said boom; characterized in that said riser and said lifting jack are individually and independently connected to said support base, and in that the load-carrying fork-type brackets of said crane move on rollers along the vertical plane of said riser, the movement being controlled by a pendular truss connecting pivotably said brackets with said boom at a point intermediate the termini of said boom.

References Qited by the Examiner UNITED STATES PATENTS 2,980,271 4/1961 Ulinski 214-131 X FOREIGN PATENTS 1,308,396 9/1962 France.

1,350,907 12/1963 France.

a ANDRES H. NIELSEN, Primary Examiner.

SAMUEL F. COLEMAN, EVON C. BLUNK,

Examiners. A. L. LEVINE, Assistant Examiner. 

1. A CRANE COMPRISING A SUPPORT BASE; A RISER CONNECTED AT ITS LOWER EXTREMITY TO SAID SUPPORT BASE; A PAIR OF LEVERS PIVOTALLY CONNECTED AT A FIRST END THEREOF TO THE UPPER EXTREMITY OF SAID RISER; A BOOM PIVOTALLY CONNECTED AT ONE TERMINUS THEREOF TO THE SECOND END OF SAID LEVERS; AND A LIFTING JACK COMPRISING A CYLINDER AND A PISTON WITHIN SAID CYLINDER, SAID PISTON BEING CONNECTED TO SAID BOOM AT A POINT INTERMEDIATE THE TERMINI OF SAID BOOM; CHARACTERIZED IN THAT SAID CYLINDER OF SAID LIFTING JACK AND SAID RISER ARE INDIVIDUALLY AND INDEPENDENTLY CONNECTED TO SAID SUPPORT BASE, THE FORMER PIVOTALLY AND THE LATTER FIXEDLY. 